Locomotive



1.628.095 May 0' w, E. WOODARD Locomo'nvs Filed April 22. 1924 2 Sheets-Sheet l IWII'N fSV I iplmroni v Arron wars w. E. WOODARD LOCOMOTIVE May 10, 1927. 1,628,095

Filed April 22. 1924 2 Sheets-Sheet 2 WITNESS 'mkfmd ATTORNEYS Patented May 10, 1927.

WILLIAM E. WOODARD, OF FOREST HILLS, NEW YORK.

LOCOMOTIVE.

Application filed April 22,

This invention relates to locomotives and its nature, objects and advantages will be best understood from the following, refer ence being had to the drawings, in which Fig. 1 an end elevation of a driving axle and its wheels equipped with lateral motion means in accordance with my invention;

Fig. 2 is a diagrammatic view illustrating the forces set up in curving;

Fig. 3 is a diagrammatic illustration of what occurs in curving in a wheel base arranged in accordance with my invention; and

Fig. 4 is a diagrammatic illustration of what occurs in curving in a wheel base of ordinary arrangement.

It has been a matter of observation that the inner rails on railway curves show greater wear than the outer rails, and no satisfactory explanation appears to have been offered for this well known fact.

The American Railway Engineering Association, at its 1923 annual meeting, at Chicago, received a report from its special committee on stresses in railroad track in which it was shown by experimental data that under certain conditions the vertical rail pressures of the inner driving wheels of a locomotive passing a curve is very high. This high vertical stress in the case of a Santa Fe (2-10-2) type locomotive occurred under the third and fourth driversprincipally under the fourth inner driverand ran as high as twice the normal vertical weight at the bearing of the wheel tread upon the rail.

This unequal distribution of vertical stresses on certain of the inner wheels was checked by test on a number of different dcsigns of locomotives and the same general results found. In general, it was demonstrated that these high vertical loads oc curred at the intermediate drivers (No. 3 and l drivers on the 2-102 class, or No. 2 and 3 drivers on the 2S-Q class) on the inner rail of the curve and at low speeds.

The explanation olfered in the report was that this inequality was due to some unexplained action of the springs and equalizers of the locomotive.

Mathematical analysis of the above noted facts, however, shows that the erratic action of the springs and equalizers is not responsible for the concentration of loads noted, but that the real reason lies in the following:

1924. Serial No. 708,131.

\Vhen a locomotive is praising around a curve, the structure of the locomotive stands substantially normal (at right angles to) the rail heads of the curve, as shown in Fig. L. There is therefore a horizontal component tending to more the entire mass of the locomotive towards the inner side of the curve, depending in amount upon the elevation of the outer rail of the curve and speed. 1

It is evident that when the engine passes through the curve at a speed at which the centrifugal force of the mass of the locomotive equals this horizontal component, it disappears. In ordinary terms. this is known as centrifugal speed (speed at which there is no horizontal component, due to the inclination of the locomotive at either rail of the curve).

It is further evident that when a locomotive passes through a curve at low speed this horizontal component must be resisted by the wheels pressing against the inner rail of the curve. The superstructure of the locomotive, which is carried upon the frames and boxes, is a rigid structure incapable of lateral deflection, and the horizontal forces due to the inclination of the structure are transi'nitted to the wheels through the faces of the driving boxes bearing against the wheel hubs, as shown in Fig. 2.

The driving wheels, of course, naturally follow the cur ature of the rails and. therefore, the superstructure being a rigid structure can bear laterally only upon one or two of the driving wheel hubs. When a lid-2 engine, for example, is going around a 10 degree curve at low speed, there is a lateral. force of about 8 percent of the weight of the superstructure of the locomotive. This lateral force must be taken up on the drivers at points adjacent to the horizontal center of gravity of the superstructure. and it is apparent that the entire amount of this hori Zontal force will be concentrated upon one or two drivers at or near the center of the wheel base of the locomotive.

In Fig. 4 I have diagrammatically shown the theoretical position taken by the driving wheels relative to the driving boxes and loco motive structure on the curve: At number 1 driving wheel, the front driving box touches the driving wheel hub on the outer side of the curve. Number 2 driver is more or less free to float. The clearance between the driving boxes and the hubs may be upon ither side. Number 3 driver is in the same condition as number Number 4 driver the driving box on the inner side of the curve bears hard against the driving wheel hub on account of the lateral reaction. Number driver free. The lateral reaction in practice is probably distributed between drivers 3 and t.

Computations show that this analysis of the condition will produce vertical forces on number 4 driver, which correspond with the experimental results obtained in the report of the special committee on stresses in railroad track of the American Railway Engineering Association. This analysis further explains the observations noted in the test referred to, that at centrifugal speeds the abnormal concentration of loads on the inner drivers disappears.

It is evident that this condition must exist to a greater or degree on all types of locomotives having rigid driving wheel base, as it is impossible to make the rigid superstructure of the locomotive conform to the curvature of the track and at low speeds the lateral pressures are bound to be concentrated at one or more driving wheels, producing the heavy vertical concentration of weight noted.

I propose to overcome this difficulty by the use of driving axles so designed as to be capable of a certain amount of lateral motion and, in the preferred form, apply this con slruction to the intermediate axles on any locomotive drivin wheel arrangement. For example, on a 2-10-2 locomotive I would apply such device to axles 3 and t.

It will be seen at once that if the axles yield laterally the lateral force above described as result of the elevation of curve will be distributed among a number of axles, doing away with the heavy concentration of load found in the ordinary construction.

With axles capable of yielding laterally, the theoretical position of driving boxes and driving wheel hubs for a 2-10-2 locomotive on a degree curve would be as diagrammatically indicated in Fig. 3; that s. at number 1 driver. the driving box on the outer side of the curve would touch the dri ing wheel hub. it number 1% driver. the inner driving box would touch the driving whee hub. Similarly, the inner boxes on 3, 4 and 5 would touch the ro spending inner driving wheel hubs. This means the lateral pressure would be dist-ributcd over a number of axles and the vertical eeaears reaction likewise distributed and thereby greatly reduced.

To accomplish this, I. propose to use a form of lateral motion axle similar to that described in my Patent No. 1,452,862 issued April 24, 1923, or similar to that described in previous patents issued to myself and Mr. Riegel, Nos. 1,181,194. 1,181,195, and 1,181,196, all issued May 2, 1916. Other forms of laterally controlled driving axles might also be used, but I prefer to use one of the above forms.

In Fig. 1, I have shown the arrangement of my Patent #1351862. Weight on the s1 rings 7 is transmitted to the boxes 8 through the interposed saddles 9. one leg of each of which rests on the box and the other on a bell crank lever 10 mounted on a box for rocking movement. The depending arm of each bell crank is adapted to abut against a part of the cross tie 11, so that as a box moves inwardly during curving, the bell crank is rocked and the saddle tilted whereby the crank carries a part of the load yieldingly resisting lateral motion and serving to center the parts when the curve has been passed through.

In Fig. 3 such lateral motion devices have been applied to numbers 3 and 4 axles.

I am aware that lateral motion devices such as above described and as shown and described in the patents enumerated and also in others, have been applied to driving wheel axles but they have been applied to end drivers, not for the purpose, however, of distributing lateral and therefore vertical stresses on the inner rail, but, on the contrary, to relieve the outer rail of the blow when a curve is entered.

I claim:

1. A locomotive wheel base having three or more closely spaced axles with their heels, and having means for distributing among the intermediate wheels of the base the inwa'd force due to the rail elevation on a curve which is unbalanced by centrif ug'al force.

2. A locomotive wheel base having three or more closely spaced axles with their wheels. and having means for distributing among the intermediate wheels of the base the inward force due to the rail elevation on a curve which is unbalanced by centrifugal force. said means comprising boxes yield ingly positioned in the frame.

In testimony whereof, I have hereunto signed my name.

WILLIAM \VOODARD. 

